FPV Goggle Audio Recorder

This thing is a USB powered digital microphone that records to SD card. It uses a Waveshare RP2040 Zero, ICS43434 mic, and SD card reader. The linked code is intened to be used as an audio recorder for FPV goggles that don't have a mic (like DJI). Just power it on, and it records RMS compressed audio in .raw format, power it down and the data is safe, sd card ready for the next power up recording session. When a USB-C to C cable is connected to the charging jack of my Goggles 3, audio records when I power on the goggles, and stops when I power them down. I convert the raw files to wav using Audacity "import/raw data/ 22050 bit rate". I tried many code iterations that record directly to wav, and file/sd card corruption occurs too often. While theoretically still possible, I have never seen file corruption with the the current code. The RMS compression parameters work well for evening audio levels of neaby voices, and distant subtle sounds, without too much background noise. Audio qualit